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Nakano H, Inoue S, Minegishi Y, Igarashi A, Tokairin Y, Yamauchi K, Kimura T, Nishiwaki M, Nemoto T, Otaki Y, Sato M, Sato K, Machida H, Yang S, Murano H, Watanabe M, Shibata Y. Effect of hyperhomocysteinemia on a murine model of smoke-induced pulmonary emphysema. Sci Rep 2022; 12:12968. [PMID: 35902671 PMCID: PMC9334265 DOI: 10.1038/s41598-022-16767-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 07/15/2022] [Indexed: 11/15/2022] Open
Abstract
Hyperhomocysteinemia was reported to enhance endoplasmic reticulum (ER) stress and subsequent apoptosis in several cells. However, the precise mechanisms of smoking susceptibility associated with hyperhomocysteinemia has not been fully elucidated. This study included 7- to 9-week-old C57BL6 male mice induced with hyperhomocysteinemia and were exposed to cigarette smoke (CS). A549 cells (human alveolar epithelial cell line) were cultured with homocysteine and were exposed to cigarette smoke extract (CSE) to observe cell viability and expression of proteins related to the ER stress. After 6 months of CS exposure, pulmonary emphysema was more severely induced in the group under the condition of hyperhomocysteinemia compared to that in the control group. The apoptotic A549 cells increased as homocysteine concentration increased and that was enhanced by CSE. Protein expression levels of ER stress markers were significantly increased after simultaneous stimulation. Notably, vitamin B12 and folate supplementation improved ER stress after simultaneous stimulation of A549 cells. In this study, we showed that hyperhomocysteinemia exacerbates CS exposure-induced emphysema in mice, suggesting that hyperhomocysteinemia and CS stimulation enhance ER stress and subsequent induced apoptosis in alveolar epithelial cells. It was suggested that there is a synergistic effect between homocysteine and CS.
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Affiliation(s)
- Hiroshi Nakano
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, 2-2-2 Iida-Nishi, Yamagata, 990-9585, Japan
| | - Sumito Inoue
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, 2-2-2 Iida-Nishi, Yamagata, 990-9585, Japan.
| | - Yukihiro Minegishi
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, 2-2-2 Iida-Nishi, Yamagata, 990-9585, Japan
| | - Akira Igarashi
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, 2-2-2 Iida-Nishi, Yamagata, 990-9585, Japan
| | - Yoshikane Tokairin
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, 2-2-2 Iida-Nishi, Yamagata, 990-9585, Japan
| | - Keiko Yamauchi
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, 2-2-2 Iida-Nishi, Yamagata, 990-9585, Japan
| | - Tomomi Kimura
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, 2-2-2 Iida-Nishi, Yamagata, 990-9585, Japan
| | - Michiko Nishiwaki
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, 2-2-2 Iida-Nishi, Yamagata, 990-9585, Japan
| | - Takako Nemoto
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, 2-2-2 Iida-Nishi, Yamagata, 990-9585, Japan
| | - Yoichiro Otaki
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, 2-2-2 Iida-Nishi, Yamagata, 990-9585, Japan
| | - Masamichi Sato
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, 2-2-2 Iida-Nishi, Yamagata, 990-9585, Japan
| | - Kento Sato
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, 2-2-2 Iida-Nishi, Yamagata, 990-9585, Japan
| | - Hiroyoshi Machida
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, 2-2-2 Iida-Nishi, Yamagata, 990-9585, Japan
| | - Sujeong Yang
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, 2-2-2 Iida-Nishi, Yamagata, 990-9585, Japan
| | - Hiroaki Murano
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, 2-2-2 Iida-Nishi, Yamagata, 990-9585, Japan
| | - Masafumi Watanabe
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, 2-2-2 Iida-Nishi, Yamagata, 990-9585, Japan
| | - Yoko Shibata
- Department of Pulmonary Medicine, Fukushima Medical University, Fukushima, Japan
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Kim H, Min H. Folic acid supplementation prevents high fructose-induced non-alcoholic fatty liver disease by activating the AMPK and LKB1 signaling pathways. Nutr Res Pract 2020; 14:309-321. [PMID: 32765812 PMCID: PMC7390741 DOI: 10.4162/nrp.2020.14.4.309] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 06/03/2020] [Accepted: 06/29/2020] [Indexed: 12/01/2022] Open
Abstract
BACKGROUND/OBJECTIVES The present study aimed to evaluate the effects of folic acid supplementation in high-fructose-induced hepatic steatosis and clarify the underlying mechanism of folic acid supplementation. MATERIALS/METHODS Male SD rats were fed control, 64% high-fructose diet, or 64% high-fructose diet with folic acid for eight weeks. Plasma glutamate-pyruvate transaminase, glutamate-oxaloacetate transaminase, lipid profiles, hepatic lipid content, S-adenosylmethionine (SAM), and S-adenosylhomocysteine (SAH) were measured. RESULTS The HF diet significantly increased hepatic total lipid and triglyceride (TG) and decreased hepatic SAM, SAH, and SAM:SAH ratio. In rats fed a high fructose diet, folic acid supplementation significantly reduced hepatic TG, increased hepatic SAM, and alleviated hepatic steatosis. Moreover, folic acid supplementation in rats fed high fructose enhanced the levels of phosphorylated AMP-activated protein kinase (AMPK) and liver kinase B (LKB1) and inhibited phosphorylation of acetyl coenzyme A carboxylase (ACC) in the liver. CONCLUSIONS These results suggest that the protective effect of folic acid supplementation in rats fed high fructose may include the activation of LKB1/AMPK/ACC and increased SAM in the liver, which inhibit hepatic lipogenesis, thus ameliorating hepatic steatosis. The present study may provide evidence for the beneficial effects of folic acid supplementation in the treatment of non-alcoholic fatty liver disease.
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Affiliation(s)
- Hyewon Kim
- Department of Food and Nutrition, College of Bio-Nano Science, Hannam University, Daejeon 34054, Korea
| | - Hyesun Min
- Department of Food and Nutrition, College of Bio-Nano Science, Hannam University, Daejeon 34054, Korea
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Elshorbagy AK, Graham I, Refsum H. Body mass index determines the response of plasma sulfur amino acids to methionine loading. Biochimie 2020; 173:107-113. [DOI: 10.1016/j.biochi.2020.03.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 03/02/2020] [Indexed: 01/02/2023]
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Novel treatment strategies for chronic kidney disease: insights from the animal kingdom. Nat Rev Nephrol 2018; 14:265-284. [PMID: 29332935 DOI: 10.1038/nrneph.2017.169] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Many of the >2 million animal species that inhabit Earth have developed survival mechanisms that aid in the prevention of obesity, kidney disease, starvation, dehydration and vascular ageing; however, some animals remain susceptible to these complications. Domestic and captive wild felids, for example, show susceptibility to chronic kidney disease (CKD), potentially linked to the high protein intake of these animals. By contrast, naked mole rats are a model of longevity and are protected from extreme environmental conditions through mechanisms that provide resistance to oxidative stress. Biomimetic studies suggest that the transcription factor nuclear factor erythroid 2-related factor 2 (NRF2) offers protection in extreme environmental conditions and promotes longevity in the animal kingdom. Similarly, during months of fasting, immobilization and anuria, hibernating bears are protected from muscle wasting, azotaemia, thrombotic complications, organ damage and osteoporosis - features that are often associated with CKD. Improved understanding of the susceptibility and protective mechanisms of these animals and others could provide insights into novel strategies to prevent and treat several human diseases, such as CKD and ageing-associated complications. An integrated collaboration between nephrologists and experts from other fields, such as veterinarians, zoologists, biologists, anthropologists and ecologists, could introduce a novel approach for improving human health and help nephrologists to find novel treatment strategies for CKD.
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Shlafman N, Shaldubin S, Applebaum J, Belmaker RH, Levine J. No gross abnormality of plasma homocysteine after acute methionine loading in clinically stabilized patients with schizophrenia. Asian J Psychiatr 2010; 3:64-6. [PMID: 23051192 DOI: 10.1016/j.ajp.2010.03.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2009] [Revised: 01/31/2010] [Accepted: 03/07/2010] [Indexed: 10/19/2022]
Abstract
Homocysteine is reported to be a risk factor for schizophrenia. The methionine loading test evaluates the summation of a multitude of enzymatic pathways associated with homocysteine metabolism. Using a challenge paradigm, we measured homocysteine levels in 10 chronic schizophrenia patients and five controls at baseline and 3h after 100mg/kg oral methionine. This pilot study failed to detect a gross abnormality of plasma homocysteine level after acute methionine load in patients with schizophrenia. Elevations in plasma homocysteine reported in schizophrenia do not derive from a dynamic abnormality in methionine metabolism in this challenge paradigm.
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Affiliation(s)
- Nurit Shlafman
- Faculty of Health Sciences, Ben Gurion, University of the Negev, Beersheva, Israel
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Apeland T, Kristensen O, Mansoor MA. The aminothiol redox status in haemodialysis patients does not improve with folate therapy. Scandinavian Journal of Clinical and Laboratory Investigation 2009; 69:265-71. [DOI: 10.1080/00365510802521143] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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The cobalt–albumin binding assay: Insights into its mode of action. Clin Chim Acta 2008; 387:120-7. [DOI: 10.1016/j.cca.2007.09.018] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2007] [Revised: 09/02/2007] [Accepted: 09/24/2007] [Indexed: 02/01/2023]
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Likogianni V, Janel N, Ledru A, Beaune P, Paul JL, Demuth K. Thiol compounds metabolism in mice, rats and humans: comparative study and potential explanation of rodents protection against vascular diseases. Clin Chim Acta 2006; 372:140-6. [PMID: 16712825 DOI: 10.1016/j.cca.2006.03.035] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2006] [Revised: 03/30/2006] [Accepted: 03/30/2006] [Indexed: 11/22/2022]
Abstract
BACKGROUND Rodents are often used as animal models to dissect mechanisms underlying hyperhomocysteinemia atherogenicity in humans. However, neither wild-type rodents nor cystathionine beta-synthase deficient mice develop spontaneous atherosclerosis. We investigated whether species-specific differences in thiols metabolism may explain the respective sensitivity of rodents and humans to hyperhomocysteinemia. METHODS Thiols and vitamins B levels were determined in normohomocysteinemic humans and rodents, and in hyperhomocysteinemic mice. RESULTS In basal status, although plasma homocysteine, cysteine and cysteinylglycine levels were lower, glutathione levels were higher in mice than in humans (4.0+/-1.6 vs. 7.9+/-2.2, P<0.0005; 147.4+/-40.3 vs. 278.5+/-50.0, P<0.0001; 2.3+/-0.7 vs. 36.6+/-7.3, P<0.0001; and 70.9+/-20.1 vs. 4.6+/-1.6, P<0.0001). Serum vitamin B12 and folate levels were 2.5- and 7.7-fold higher in rats than in humans. In wild-type mice, the increase in plasma Hcy levels induced by methionine-enriched diet was accompanied by a proportional increase in GSH levels. CONCLUSION GSH levels are enough to modulate Hcy effects in normo- and hyperhomocysteinemic mice but not in humans. This rodents characteristic, likely supported by species differences in the relative contribution of remethylation and transsulfuration pathways, may partly explain their protection against atherosclerosis.
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Affiliation(s)
- Vasiliki Likogianni
- Assistance Publique-Hôpitaux de Paris, Service de Biochimie, Hôpital Européen Georges Pompidou, Paris, France
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Alhamdani MSS. Impairment of glutathione biosynthetic pathway in uraemia and dialysis. Nephrol Dial Transplant 2005; 20:124-8. [PMID: 15632350 DOI: 10.1093/ndt/gfh569] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Glutathione (GSH), the predominant intracellular antioxidant, reportedly has been shown to be decreased in chronic renal failure patients, which renders these patients more susceptible to oxidative damage by free radicals. To our knowledge, the ability of erythrocytes to normalize the GSH level by de novo synthesis in uraemic and dialysis patients has not been studied previously. The main goal of the present study was to measure the activities of the enzymes that are responsible for de novo GSH generation, namely gamma-glutamylcysteine synthetase (gamma-GCS) and glutathione synthetase (GSH-S), in erythrocytes from uraemic and dialysis patients. METHODS Erythrocyte total GSH level and gamma-GCS and GSH-S activities as well as plasma malondialdehyde (MDA) levels were measured in 19 non-dialysis patients (ND), 34 haemodialysis patients (HD), 22 continuous ambulatory peritoneal dialysis patients (CAPD) and 21 normal healthy controls. The effect of a single haemodialysis session was determined in 16 HD patients. RESULTS Significant decreases in GSH levels and gamma-GCS activity but not GSH-S were observed in ND, HD and CAPD patients compared with controls. However, GSH levels as well as gamma-GCS and GSH-S activities were not different among the ND, HD and CAPD patients. The decrease in GSH was strongly and positively correlated with the decrease in gamma-GCS in ND, HD and CAPD patients (r = 0.717, P<0.001; r = 0.854, P<0.001; and r = 0.603, P<0.01, respectively). In addition, plasma MDA was negatively correlated with gamma-GCS in ND, HD and CAPD patients (r = 0.721, P<0.001; r = 0.560, P<0.01; and r = 0.585, P<0.01, respectively). A single dialysis session had no effect on GSH level or on gamma-GCS and GSH-S activities. Only a significant reduction in MDA was observed at the end of dialysis. CONCLUSIONS The activity of the rate-limiting enzyme in GSH biosynthesis, gamma-GCS, was significantly decreased in uraemic and dialysis patients, which explains, at least in part, frequent reports of reduced GSH levels in these patients. The decrease in gamma-GCS activity may have been secondary to inhibitory effects from uraemic factors that are not removed by standard dialysis. However, this assumption does not exclude the possibility of down-regulation of gamma-GCS protein expression and further studies in this context are recommended.
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Affiliation(s)
- Mohamed-Saiel S Alhamdani
- Department of Clinical Biochemistry, College of Pharmacy, Al-Mustainsiriyah University, Baghdad, Iraq.
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Vincent AS, Lim BG, Tan J, Whiteman M, Cheung NS, Halliwell B, Wong KP. Sulfite-mediated oxidative stress in kidney cells. Kidney Int 2004; 65:393-402. [PMID: 14717909 DOI: 10.1111/j.1523-1755.2004.00391.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Chronic renal failure has been associated with oxidative stress. Serum sulfite, sulfate, cysteine, homocysteine, cysteine sulfinic acid, and gamma-glutamylcysteine are elevated in patients on hemodialysis, suggesting an accelerated catabolism of sulfur-containing amino acids or a reduced elimination of sulfite/sulfate, or both. Administration of metabisulfite has also been shown to damage kidney cells. METHODS Measurement of reactive oxygen species (ROS) was performed with the fluorescence of dichlorofluorescein (DCF), and that of intracellular ATP was by the luciferin-luciferase reaction. Oxidation of sulfite and succinate by isolated mitochondria from rat kidney was monitored polarographically. The fluorescent probe, 5, 5', 6, 6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolcarbocyanine iodide (JC-1) was employed to assess any loss in membrane potential in energized respiring mitochondria. Activities of glutamate and malate dehydrogenases (GDH, MDH, respectively) were assayed by the spectrophotometric measurement of NADH. Sulfite was determined by HPLC-fluorimetric measurement of monochlorobimane-sulfite and cell viability was by the MTT procedure. RESULTS An immediate increase in ROS followed exposure of Madin-Darby canine kidney (MDCK), type II, and opossum kidney (OK) cells to 5-500 micromol/L sulfite. Depletion of intracellular ATP was also observed. A low rate of oxidation of 100 micromol/L sulfite was observed polarographically in isolated kidney mitochondria, but ADP-stimulated State 3 respiration was not apparent. ATP biosynthesis from the oxidation of glutamate in rat kidney mitochondria was significantly inhibited by coincubation with 100 micromol/L sulfite; this was not the case with malate, succinate, and TMPD/ascorbate. However, activities of both GDH and MDH in kidney mitochondrial extract were inhibited. The mitochondrial membrane potential and cell viability were not compromised. CONCLUSION Micromolar sulfite elicited an immediate increase in ROS in MDCK, type II, and OK cells. This was accompanied by a depletion of intracellular ATP, which could be explained by its inhibitory effect on mitochondrial GDH. Although MDH was similarly inhibited, the impact was buffered by the high level of this enzyme in kidney mitochondria.
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Affiliation(s)
- Annette S Vincent
- Department of Biochemistry, Faculty of Medicine, National University of Singapore, Singapore
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Obeid OA, Johnston K, Emery PW. Plasma taurine and cysteine levels following an oral methionine load: relationship with coronary heart disease. Eur J Clin Nutr 2003; 58:105-9. [PMID: 14679374 DOI: 10.1038/sj.ejcn.1601755] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
OBJECTIVE To test the hypothesis that endogenous synthesis of taurine from methionine is impaired in people with coronary heart disease (CHD). DESIGN Nested case-control. SUBJECTS Indian Asian and white European males aged 35-60 y. Both racial group included patients with CHD and healthy controls. Samples from 20 subjects in each of the four groups were selected at random. INTERVENTION Fasting blood samples were taken before and 6 h after consumption of methionine (100 mg/kg body weight) MEASUREMENTS Plasma concentrations of taurine, cysteine, pyridoxal-5-phosphate and 4-pyridoxic acid. RESULTS Fasting plasma taurine values were higher in Indian Asian cases than controls, but not significantly different between European cases and controls. Postload taurine values were higher in cases than controls in both racial groups (P=0.002). Fasting plasma cysteine was higher in cases than controls (P=0.002) and higher in Indian Asians than Europeans (0.007), but there were no significant differences between any of the groups in postload cysteine values, nor in plasma pyridoxal-5-phosphate or 4-pyridoxic acid. CONCLUSIONS Taurine production from methionine was not impaired in patients with CHD, but fasting plasma cysteine was higher in CHD cases than controls.
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Affiliation(s)
- O A Obeid
- Department of Human Nutrition, St Bartholomew's and Royal London School of Medicine and Dentistry, Queen Mary and Westfield College, London, UK
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Suliman ME, Stenvinkel P, Bárány P, Heimbürger O, Anderstam B, Lindholm B. Hyperhomocysteinemia and its relationship to cardiovascular disease in ESRD: influence of hypoalbuminemia, malnutrition, inflammation, and diabetes mellitus. Am J Kidney Dis 2003; 41:S89-95. [PMID: 12612961 DOI: 10.1053/ajkd.2003.50093] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND In the general population, a mildly elevated plasma total homocysteine (tHcy) level is an independent and graded risk factor for cardiovascular disease (CVD). In patients with end-stage renal disease (ESRD), CVD is highly prevalent and a major cause of premature mortality, and plasma tHcy levels are as much as three to four times greater than in the general population. Several other risk factors, such as diabetes mellitus (DM), inflammation, and malnutrition, also are prevalent and contribute to CVD in patients with ESRD, and there are strong associations between inflammation, malnutrition, and hypoalbuminemia in these patients. Several investigations in patients with ESRD have shown the important role of vitamin status for plasma tHcy, but little attention has been given to the influence of nutritional status. However, it is obvious that hypoalbuminemia is of interest because a substantial fraction of tHcy (>70%) is protein bound, mainly to albumin. RESULTS In studies of patients with ESRD in whom the prevalence of hyperhomocysteinemia was very high (>90%), tHcy level was strongly related to serum albumin level, and patients with malnutrition had lower levels of both tHcy and serum albumin than those with normal nutritional status. Furthermore, inflammation, DM, and CVD are associated with hypoalbuminemia and therefore a lower degree of hyperhomocysteinemia. In our studies, in different groups of patients with ESRD, we showed that greater tHcy levels were associated with lower CVD mortality. However, this apparently paradoxical association between lower CVD mortality and lower plasma tHcy levels (although still abnormally high) does not refute the concept that hyperhomocysteinemia is a risk factor for CVD because almost all patients may have had long-standing elevated plasma tHcy levels within a range that makes them prone to develop atherosclerosis. Instead, a potentially detrimental effect of hyperhomocysteinemia on CVD in patients with ESRD may be obscured by the influence of hypoalbuminemia, whatever the cause, because hypoalbuminemia and its causes are strong predictors of mortality. CONCLUSION Our findings imply that nutritional status and serum albumin level, as well as the presence of inflammation and DM, should be taken into consideration when evaluating tHcy as a risk factor for CVD in patients with ESRD.
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Affiliation(s)
- Mohamed E Suliman
- Division of Baxter Novum, Department of Clinical Science, Karolinska Institutet, Huddinge University Hospital, Stockholm, Sweden
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Suliman ME, Stenvinkel P, Heimbürger O, Bàràny P, Lindholm B, Bergström J. Plasma sulfur amino acids in relation to cardiovascular disease, nutritional status, and diabetes mellitus in patients with chronic renal failure at start of dialysis therapy. Am J Kidney Dis 2002; 40:480-8. [PMID: 12200798 DOI: 10.1053/ajkd.2002.34887] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Sulfur amino acids (sAAs) are potential candidates as risk factors for cardiovascular disease (CVD). However, we recently reported that chronic hemodialysis patients with CVD had a greater prevalence of malnutrition, hypoalbuminemia, and lower plasma total homocysteine (tHcy) levels than those without CVD. In this cross-sectional study, we examined the relationship of plasma sAAs to CVD and nutritional status in 151 patients with chronic renal failure (CRF) close to the start of regular dialysis treatment (33 +/- 7 days before the first dialysis treatment). Clinical signs of CVD were present in 32% of patients with CRF, 41% had malnutrition assessed by subjective global nutritional assessment (SGNA) score, and 26% had diabetes mellitus (DM). Plasma tHcy levels were high in 91% of patients, as were plasma total cysteine (tCys) levels, whereas plasma methionine (Met) and taurine (Tau) levels were normal. Patients with CRF who had CVD were older, more often malnourished, and had lower tHcy and serum albumin (s-albumin) levels and a greater frequency of DM than those without CVD. Plasma tCys, Met, and Tau levels did not differ between patients with CRF with and without CVD. The tCys-tHcy ratio was higher in patients with CVD and related to SGNA score and DM. Moreover, this ratio, but not tHcy or tCys level, correlated with age and triglyceride, total cholesterol, and apolipoprotein B levels. Malnutrition and hypoalbuminemia were associated with low plasma sAA levels (tHcy, Met, and Tau); tCys was related to s-albumin level, but not SGNA score. Among patients with diabetes, sAA levels did not differ between patients with and without CVD or between malnourished and well-nourished patients. In conclusion, patients with CRF at the start of dialysis treatment with CVD were more often diabetic, malnourished, and had lower s-albumin and tHcy levels and a higher tCys-tHcy ratio than patients with no CVD. tCys-tHcy ratio, but not tHcy or tCys levels per se, was related to cardiovascular risk factors, suggesting that cysteine may have a role in the development of CVD. Malnutrition, hypoalbuminemia, and DM in patients with CRF influence sAA levels, mainly plasma tHcy, which should be considered when evaluating hyperhomocysteinemia as a cardiovascular risk factor.
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Affiliation(s)
- Mohamed E Suliman
- Division of Renal Medicine and Baxter Novum, Department of Clinical Science, Karolinska Institutet, Huddinge University Hospital, Stockholm, Sweden
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Abstract
BACKGROUND Plasma aminothiols, including homocysteine, cysteine, and glutathione, function as an important extracellular redox system. We examined the plasma aminothiol concentration and redox status in ten chronic hemodialysis patients compared to ten age-matched healthy subjects. METHODS Plasma levels of reduced, free oxidized, and protein-bound homocysteine, cysteine, cysteinylglycine, and glutathione were determined using high-pressure liquid chromatography (HPLC). RESULTS Total plasma homocysteine, cysteine, and cysteinylglycine levels were significantly elevated in hemodialysis patients before dialysis compared to healthy subjects. Total plasma concentration of cysteine and homocysteine significantly decreased after hemodialysis. The ratio of free oxidized to free reduced homocysteine, cysteine, cysteinylglycine, and glutathione were each significantly elevated before dialysis compared to healthy subjects, and decreased significantly by the end of dialysis. The free oxidized to reduced ratio of cysteine and homocysteine were also significantly correlated with total plasma concentrations. CONCLUSIONS Plasma aminothiols are excessively oxidized in uremia, while the hemodialysis procedure is restorative of redox status. Oxidized aminothiols are candidate uremic toxins.
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Affiliation(s)
- Jonathan Himmelfarb
- Maine Medical Center and Maine Medical Center Research Institute, Portland, Maine 04102, USA.
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Lindner A, Bankson DD, Stehman-Breen C, Mahuren JD, Coburn SP. Vitamin B6 metabolism and homocysteine in end-stage renal disease and chronic renal insufficiency. Am J Kidney Dis 2002; 39:134-45. [PMID: 11774112 DOI: 10.1053/ajkd.2002.29904] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Homocysteine (tHcy) is a risk factor for atherosclerosis in patients with end-stage renal disease and chronic renal insufficiency (CRI). Vitamin B6 deficiency may result in high tHcy levels, especially after a methionine load (PML). Therefore, we evaluated vitamin B6 metabolism and tHcy (fasting and PML) levels in patients with CRI and those on hemodialysis (HD) therapy before and during high-dose sequential vitamin B6 and folic acid supplementation in male patients (27 patients, HD, 17 patients, CRI) and 19 age-matched healthy controls. Vitamin B6 doses were 100 mg/d in patients with CRI and 200 mg/d in HD patients, plus folic acid (5 mg/d), for more than 3 months in each period. We analyzed vitamin B6 metabolites by high-performance liquid chromatography in plasma and red blood cells (RBCs) and fasting tHcy in all cases and PML in subgroups of 11 HD patients and 14 patients with CRI. We found vitamin B6 deficiency and high tHcy (fasting and PML) levels in all patients. Plasma and RBC levels of pyridoxal and pyridoxal phosphate were abnormally low, whereas levels of pyridoxic acid (PA), an end product of vitamin B6 metabolism, were extremely high in both groups. Fasting and PML tHcy levels were partially resistant to vitamin B6 supplements, with different response patterns in HD patients and those with CRI. Thus, the PML defect was more responsive to folic acid in HD patients, whereas vitamin B6 partially reduced PML tHcy levels in patients with CRI. Resistance of tHcy to vitamin B6 treatment in patients with CRI and HD patients is not caused by poor absorption or low tissue stores. Rather, nonvitamin factors or potentially toxic PA levels may be implicated in abnormal vitamin B6 and/or tHcy metabolism during renal insufficiency.
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Affiliation(s)
- Armando Lindner
- Department of Medicine, Veteran's Affairs Puget Sound Health Care System, University of Washington, Seattle, WA 98108, USA.
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Sunder-Plassmann G, Hörl WH. Pathophysiology and Treatment of Hyperhomocysteinemia in End-Stage Renal Disease Patients. Hemodial Int 2001; 5:86-91. [PMID: 28452434 DOI: 10.1111/hdi.2001.5.1.86] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The pathophysiology of hyperhomocysteinemia in end-stage renal disease (ESRD) patients includes impaired remethylation of homocysteine (Hcy) to methionine, inhibition of extrarenal Hcy metabolism by uremic solutes, a block in decarboxylation of cysteinesulfinic acid, impaired [adenosylmethionine]/[adenosylhomocysteine] ratio, and a probable impairment of renal Hcy metabolism and excretion. Treatment of hyperhomocysteinemia in ESRD patients includes administration of folic acid (1 - 15 mg per day). No additional effects have been observed with higher folic acid doses, folinic acid, or 5-methyltetrahydrofolate. Oral supplementation with vitamin B 6 and vitamin B 12 has no effect, but some studies reported a decrease of plasma Hcy with high intravenous vitamin doses. Effective reduction of plasma total Hcy (tHcy) in patients treated with super-flux hemodialyzers suggests the removal of uremic toxins with inhibitory activities against enzymes involved in the extrarenal Hcy metabolism.
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Affiliation(s)
- G Sunder-Plassmann
- Division of Nephrology, Department of Medicine, University of Vienna, Vienna, Austria
| | - Walter H Hörl
- Division of Nephrology, Department of Medicine, University of Vienna, Vienna, Austria
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